Common base class for Explain_join and Explain_table. More...

Inheritance diagram for anonymous_namespace{opt_explain.cc}::Explain_table_base:

Protected Member Functions
	Explain_table_base (enum_parsing_context context_type_arg, THD const explain_thd_arg, const THD query_thd_arg, Query_block query_block_arg=nullptr, TABLE const table_arg=nullptr)

bool	explain_partitions () override

bool	explain_possible_keys () override

bool	explain_key_parts (int key, uint key_parts)

bool	explain_key_parts_for_range_scan (const AccessPath *range_scan)
	Append names of the key parts used by a range access path to the current EXPLAIN row. More...

bool	explain_key_and_len_quick (AccessPath *range_scan)

bool	explain_key_and_len_index (int key)

bool	explain_key_and_len_index (int key, uint key_length, uint key_parts)

bool	explain_extra_common (int range_scan_type, uint keyno)

bool	explain_tmptable_and_filesort (bool need_tmp_table_arg, bool need_sort_arg)

Protected Member Functions inherited from anonymous_namespace{opt_explain.cc}::Explain
	Explain (enum_parsing_context context_type_arg, THD explain_thd_arg, const THD query_thd_arg, Query_block *query_block_arg)

virtual bool	shallow_explain ()
	Explain everything but subqueries. More...

bool	explain_subqueries ()
	Explain the rest of things after the `shallow_explain()` call. More...

bool	mark_subqueries (Item item, qep_row destination)
	Qualify subqueries with WHERE/HAVING/ORDER BY/GROUP BY clause type marker. More...

bool	prepare_columns ()
	Pre-calculate table property values for further EXPLAIN output. More...

bool	push_extra (Extra_tag tag)
	Push a part of the "extra" column into formatter. More...

bool	push_extra (Extra_tag tag, const String &arg)
	Push a part of the "extra" column into formatter. More...

bool	push_extra (Extra_tag tag, const char *arg)
	Push a part of the "extra" column into formatter. More...

virtual bool	explain_id ()

virtual bool	explain_select_type ()

virtual bool	explain_table_name ()

virtual bool	explain_join_type ()

virtual bool	explain_key_and_len ()
	fill col_key and and col_key_len fields together More...

virtual bool	explain_ref ()

virtual bool	explain_rows_and_filtered ()
	fill col_rows and col_filtered fields together More...

virtual bool	explain_extra ()

virtual bool	explain_modify_flags ()

virtual bool	can_walk_clauses ()
	Returns true if the WHERE, ORDER BY, GROUP BY, etc clauses can safely be traversed: it means that we can iterate through them (no element is added/removed/replaced); the internal details of an element can change though (in particular if that element is an Item_subselect). More...

virtual enum_parsing_context	get_subquery_context (Query_expression *unit) const

Protected Attributes
QEP_TAB *	tab {nullptr}
	The QEP_TAB which we are currently explaining. More...

const TABLE *	table {nullptr}

join_type	type {JT_UNKNOWN}

AccessPath *	range_scan_path {nullptr}

Item *	condition {nullptr}

bool	dynamic_range {false}

Table_ref *	table_ref {nullptr}

bool	skip_records_in_range {false}

bool	reversed_access {false}

Key_map	usable_keys

Protected Attributes inherited from anonymous_namespace{opt_explain.cc}::Explain
THD *const	explain_thd
	cached THD which runs the EXPLAIN command More...

const THD *	query_thd
	THD which runs the query to be explained. More...

const CHARSET_INFO *const	cs
	cached pointer to system_charset_info More...

Query_block *const	query_block
	Cached Query_block of the explained query. More...

Explain_format *const	fmt
	shortcut for thd->lex->explain_format More...

enum_parsing_context	context_type
	associated value for struct. explain More...

bool	order_list
	if query block has ORDER BY More...

const bool	explain_other
	if we explain other thread than us More...

Additional Inherited Members
Public Member Functions inherited from anonymous_namespace{opt_explain.cc}::Explain
virtual	~Explain ()=default

bool	send ()
	Explain class main function. More...

bool	can_print_clauses () const
	Tells if it is allowed to print the WHERE / GROUP BY / etc clauses. More...

Detailed Description

Common base class for Explain_join and Explain_table.

Constructor & Destructor Documentation

◆ Explain_table_base()

anonymous_namespace{opt_explain.cc}::Explain_table_base::Explain_table_base	(	enum_parsing_context	context_type_arg,
		THD *const	explain_thd_arg,
		const THD *	query_thd_arg,
		Query_block *	query_block_arg = `nullptr`,
		TABLE *const	table_arg = `nullptr`
	)

inlineprotected

Member Function Documentation

◆ explain_extra_common()

bool Explain_table_base::explain_extra_common	(	int	range_scan_type,
		uint	keyno
	)

protected

◆ explain_key_and_len_index() [1/2]

bool Explain_table_base::explain_key_and_len_index ( int key )

protected

◆ explain_key_and_len_index() [2/2]

bool Explain_table_base::explain_key_and_len_index	(	int	key,
		uint	key_length,
		uint	key_parts
	)

protected

◆ explain_key_and_len_quick()

bool Explain_table_base::explain_key_and_len_quick ( AccessPath * range_scan )

protected

◆ explain_key_parts()

bool Explain_table_base::explain_key_parts	(	int	key,
		uint	key_parts
	)

protected

◆ explain_key_parts_for_range_scan()

bool Explain_table_base::explain_key_parts_for_range_scan ( const AccessPath * range_scan )

protected

Append names of the key parts used by a range access path to the current EXPLAIN row.

For composite range access paths, recursively visit the child range scans and append their used key-part names in the same order as key and key_length.

Parameters

range_scan Range access path to explain.

Return values

false	Success.
true	Error while appending a key part name.

◆ explain_partitions()

bool Explain_table_base::explain_partitions ( )

overrideprotectedvirtual

Reimplemented from anonymous_namespace{opt_explain.cc}::Explain.

◆ explain_possible_keys()

bool Explain_table_base::explain_possible_keys ( )

overrideprotectedvirtual

Reimplemented from anonymous_namespace{opt_explain.cc}::Explain.

◆ explain_tmptable_and_filesort()

bool Explain_table_base::explain_tmptable_and_filesort	(	bool	need_tmp_table_arg,
		bool	need_sort_arg
	)

protected

Member Data Documentation

◆ condition

Item* anonymous_namespace{opt_explain.cc}::Explain_table_base::condition {nullptr}

protected

◆ dynamic_range

bool anonymous_namespace{opt_explain.cc}::Explain_table_base::dynamic_range {false}

protected

◆ range_scan_path

AccessPath* anonymous_namespace{opt_explain.cc}::Explain_table_base::range_scan_path {nullptr}

protected

◆ reversed_access

bool anonymous_namespace{opt_explain.cc}::Explain_table_base::reversed_access {false}

protected

◆ skip_records_in_range

bool anonymous_namespace{opt_explain.cc}::Explain_table_base::skip_records_in_range {false}

protected

◆ tab

QEP_TAB* anonymous_namespace{opt_explain.cc}::Explain_table_base::tab {nullptr}

protected

The QEP_TAB which we are currently explaining.

It is NULL for the inserted table in INSERT/REPLACE SELECT, and single-table UPDATE/DELETE.

Note: that you should never read quick() or condition() even for SELECT, they may change under your feet without holding the mutex; read quick and condition in this class instead.

◆ table

const TABLE* anonymous_namespace{opt_explain.cc}::Explain_table_base::table {nullptr}

protected

◆ table_ref

Table_ref* anonymous_namespace{opt_explain.cc}::Explain_table_base::table_ref {nullptr}

protected

◆ type

join_type anonymous_namespace{opt_explain.cc}::Explain_table_base::type {JT_UNKNOWN}

protected

◆ usable_keys

Key_map anonymous_namespace{opt_explain.cc}::Explain_table_base::usable_keys

protected

The documentation for this class was generated from the following file:

sql/opt_explain.cc

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ Explain_table_base()

Member Function Documentation

◆ explain_extra_common()

◆ explain_key_and_len_index() [1/2]

◆ explain_key_and_len_index() [2/2]

◆ explain_key_and_len_quick()

◆ explain_key_parts()

◆ explain_key_parts_for_range_scan()

◆ explain_partitions()

◆ explain_possible_keys()

◆ explain_tmptable_and_filesort()

Member Data Documentation

◆ condition

◆ dynamic_range

◆ range_scan_path

◆ reversed_access

◆ skip_records_in_range

◆ tab

◆ table

◆ table_ref

◆ type

◆ usable_keys